The Black Heir
by Supersaiyangirl
Summary: Xander is more than he seems and one certain Halloween all is revealed. Leading him into an exciting and dangerous new world. YAHF.


The Black Heir

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**Yes, most of this is the same as The Traitor but there is more added to extend it into full story potential.**

** I don't own either BtVS or HP.  
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Chapter 1

The figure slowly got to his feet, he put a hand to his head in an attempt to ease the headache that was forming and froze. He was alive, he should be dead, hell he was dead he was sure of it. But here he was very much alive. He frowned and looked round to see he was in a very muggle looking town, and not a British one at that. Where the bloody hell was he? The last thing he could remember was telling Kreacher to leave with the real Horxcrux, then the Inferi came, then there was nothing and he woke up here, wherever here was. A growl made Regulus to look up, there were some very short demons coming down the street towards him. Regulus smirked, it looked like someone had got themselves into something they couldn't handle and got themselves killed. Summoning demons was a dangerous thing after all. The smirk turned into a frown, there were demons on a muggle street, in plain view of the muggles, so where were the Aurors? Shrugging, he guessed he'd have to deal with it himself, not for the muggle's sake but he didn't fancy being killed by demons anytime soon, especially as he'd only just got his life back. He raised his right hand and was momentary surprised that he was holding his wand as he'd given it to Kreacher along with the locket. Chalking it up to the same weirdness that had resulted in him being alive and here, he said the spell he'd been taught by a friend.

"Sectumsempra." Regulus smirked as the demon fell down with multiple cuts to it's chest. He may have betrayed the Dark Lord, but it was still a dark wizard. It was just that Horcuxes were an evil that should not to allowed in the world. The Blacks were a dark family, but he'd always been taught that there was a limit of what should be allowed in the use of magic. Forget the Unforgivables, there were worst things in the world than them, Inferi were borderline, but Horcuxes and soul magic in general were so far past it that even the Blacks wouldn't touch it. Regulus turned to the next demon.

"Reducto!" Regulus said, and sent the demon flying into the side of a house. Regulus didn't notice the gasp that came from behind him and levelled his wand on the last demon and was about to deliver the same fate to that one when someone shouted out behind him.

"NO! Don't hurt them!" Startled Regulus turned to face the owner of the voice wand still raised. Regulus blinked at the very revealing muggle clothes the redheaded teenager was wearing. She looked very surprised to see him.

"Xander?" she asked. Regulus then schooled his face into a sneer.

"It's a demon." He said in a strong London accent, he turned to face the demon again very ready to ignore the annoying muggle.

"But, but there's a kid in there!" the girl persisted, Regulus looked over at her and raised an eyebrow in question. "There's been a spell or something, everyone's been turned into their costumes," she said in a rush when she saw he was listening. Regulus sighed, he never minded killing, but he'd always refused to kill kids before, he'd left that to the Lestrange's, and he wasn't about to start now.

"Fine," he said and turned back to the demon. "Stupefy." The red spell hit the demon in the chest and it fell to the ground. Regulus scanned the area, apart from himself and the redhead the street was empty, he relaxed from battle readiness. He went to put his wand away but found that he didn't have a wand holder and Deatheater robes didn't have pockets so it seemed he had to carry his wand.

"Xander! I thought you weren't going to hurt him!" the muggle shouted. Regulus rolled his eyes at the muggle.

"I just stunned it, if it really is a child, they'll just have a headache," he said. "And my name isn't Xander. It's Regulus Black," he raised his wand again. "But you're not going to remember any of this." Normally he would have just crucioed her and left her for the Aurors, but there was something about the girl that made him not want to hurt her. The girl's eyes widened in fear. "Obliviate!" A second later it was Regulus's eyes that widened, as the spell went right though her chest, without affecting her.

"What was that, Xander! Did you just shot me?" she cried out. Regulus just chuckled as he realised that he didn't have to worry about her as there was no way she could be a muggle, as muggles can't become ghosts. "What's so funny, mister!" she demanded her hand were now on her hips. Regulus just shock his head.

"Your a ghost," he said.

"And, hey, you're a wizard," she stated but it wasn't a question, she looked as if she'd realised something. "I'm a ghost because I dressed as one." She said ignoring the questioning look Regulus sent her, how can you dress like a ghost? Must be a muggle thing, he decided. "And you, I mean Xander," she corrected herself. "Dressed as a wizard and became, well, you." Regulus stared at her for a long time before shaking his head.

"That is... The most ridiculous thing I've ever heard!" he said. "Do you know my brother?" The girl just sighed and looked annoyed.

"Look, your Xander Harris, you dressed as a wizard!" she said. "And I'm your friend, Willow." Ah, so she does have a name, Regulus thought. "You've got to believe me! Look for yourself," she said standing by one of those muggle transportation machines. He looked at her blankly how was that meant to show him anything. Muggles are weird. She must have seen his confusion. "Look in the wing mirror." She pressed. Shaking his head, he was doing a lot of that lately, he decide to humour her and conjured a mirror, and almost dropped it. The face in the mirror wasn't his! It was the face of a teenager, seventeen at the most, he didn't have the aristocratic features that the Blacks were famous for, or the black hair or the grey eyes. The boy he was looking at had brown hair and brown eyes, he looked like, freaking, Potter! He pointed his wand at himself and whispered.

"Finite Incantatem." But nothing changed, he stilled looked like Potter. Growling he violently banished the mirror, making the girl jump a bit. Without a word he set off down the street, someone was going to hurt for this! The name of Black had suffered enough when it's heir became a Gryffindor and a blood traitor, but to make the one remaining heir look like a blood traitor was just the last straw. Willow ran after him.

"Hey! Where are you going?" she asked. Regulus smirked, it made Willow shiver.

"Too get some justice," he said coldly, his demeanour suggesting that the justice he had in mind was less then legal. He looked at her. "You said this is all a spell?" he asked her.

"I th-think so," she said, the look on Regulus's face did not belong on the features of her best friend.

"Then it can be ended," he said, he remembered something she'd said. "Costumes," he muttered.

"Huh?" Willow said.

"You said something about costumes," he said. Willow nodded, then her eyes widened.

"You don't think it was the costumes themselves that did this?" she asked. Regulus nodded slightly.

"It's possible, a time delayed charm or something," he mused. "Where did you acquire them?" he asked.

"A place called Ethan's," Willow said.

"Where is that? It's the best place to start."

"It's on the main street, that way," she said pointing. Regulus smiled, it wasn't a pleasant smile, it was one that promised pain. He set off in the direction she indicated. Willow followed him nervously.

Regulus arrived at the shop called 'Ethan's', there was a certain lack of inventiveness about that name. He was alone, something he was very glad of, he didn't want any witnesses to what he was going to do. He'd gotten rid of the 'muggle ghost' when they'd come across a dark haired girl wearing an old fashioned dress that was screaming 'demon' at any of the muggle contraptions that passed them. She was showing all the signs of being on the wrong side of a faulty Obliviate. To his annoyance they had followed him. Just before he was at the end of his tether, and about to curse them, the dark haired man called Angel had came and he'd been able to leave the two with him and slip away. Regulus walked quickly though the front of shop and headed to the back were the light was coming from, the bright steady light that the muggles used. Deciding to make a big entrance, Regulus raised his wand.

"Expulso!" He shouted and the door exploded. Regulus could hear someone curse, in a british accent from inside the room. He stepped inside and before the person could move Regulus bound him tight.

"I'm going to ask just once then I'm going to get nasty. Are you the one that cast the spell that changed everyone?" he asked in a voice that promised pain if you didn't answer. The man shook his head. Regulus smiled. "Crucio," he said. He only left it on for a few seconds but that was enough to make the man scream, pathetic. He lifted it. "Well?"

"Y-yes," the man said shaking.

"Why?"

"For the chaos!" the man said. "Think of all that chaos out there, beautiful." Chaos? Regulus could respect that, seeing as that was one of the main goal of any Deatheater raid. But it needed a purpose.

"But why?" he pressed. The man looked confused.

"Chaos needs no reason," the man said. Regulus sneered, even for the Deatheaters there had been a reason for the chaos. This man was a waste of life.

"How do I reverse it?" Regulus asked. The man didn't said anything. Regulus growled. "Don't make me ask again." The man's eyes went wide.

"The bust, break the bust," he said. Regulus smiled at him. He was about to kill the man when he realised that he might be lying. Now Regulus wasn't a legilimens, but he had another way to find out if the man was lying.

"Imperio." Regulus watched as the man's eyes glazed over. "How do I break the spell on me?"

"Breaking the bust of Janus will end the spell," the man said tonelessly. Regulus smiled and without even bothering to break the curse Regulus said.

"Avada Kedavra." The sickly green spell hit the man and that was the end of Ethan Rayne. Regulus stood, smirked and pointed his wand at the bust of Janus and said one more spell.

"Reducto." As soon as the spell hit the bust and it shattered the body of Xander Harris dropped to the floor out cold.

The wards of number 12 Grimmwauld Place were old and powerful, and had been sentient they would have realised that a person doesn't just appear out of nowhere especially the son of dead man but they were not, so they set about making the necessary changes to the wards and Family Tree. A new name appeared on the Family Tree linked to Regulus Arcturus Black, one Alexander Lavelle Harris Black, another name was added by proxy, one Jessica Harris née Lavelle. Her name in red showing that not only is she not of Black blood but is also a Squib. However she is a Squib from a powerful American Pureblood family, which is enough to trigger the next change. The gold letters that showed Sirius Black to be the current Black heir faded and reappeared on Xanders name. While Sirius Black is the oldest direct male in the bloodline baring the Black name, he was disowned by his parents before they died so the appearance of another male Black, the Pureblood son of his non-disowned brother, displaced him as the current heir of the Black family. Number 12 Grimmwauld Place went into lockdown, no non-Black could gain access to the house until the new heir took his place as the new Lord Black, however since Sirius was the only occupant at the time and the new term at Hogwarts had already started so it wasn't, currently, being used as the meeting place for the Order of the Phoenix no one would notice this for quite some time. At the same time similar changes were taking place at the British and American Ministry of magic's and at Gringotts.

Xander sat on his bed a few hours later and stared at his hands, he'd killed someone. Sure, he hadn't been in control of his body at the time, but he'd still done it. God, now he had an idea how Deadboy felt. It was like the hyena thing all over again only worse, much worse. Xander closed his eyes briefly, he could remember the deaths of so many people, people Regulus had tortured and killed or seen tortured and killed. Regulus Black wasn't really evil, he was bad and very dark, he'd had limits but he'd still killed. Xander shivered as he remembered some of the more nasty things that Regulus had done. Even his last act hadn't been one of redemption. While it could have looked that way from the outside, but really Regulus had know that there was no redemption to be had for him and he just wanted a way out from being a Deatheater. To him death was better then the humiliation of changing sides, Black honour had been drilled into him since birth. It was worse then normal for him because of his brother being a blood traitor, his mother had been much harder on him. Xander traced the black tattoo on his arm and the snake moved slightly, one of the things that hadn't left him last night. The Dark Mark, the symbol of the Deatheaters burnt into his own skin. Xander sighed and picked up the wand he'd used last night and felt the familiar tingle of magic go up his arm. At least with this it wasn't so bad, it wasn't as if Voldemort was real after all. Xander groaned, he'd so just jinxed himself. After a few minutes passed and nothing happened Xander relaxed, but then his arm started to burn.

The burning stopped half an hour later and Xander sighed in relief. He really should talk to Giles about this but it was so late that it was technically morning, far too late disturb anyone alive. Xander undressed and placed his wand, it was his it just felt right, on the table by his bed in easy reach should he need it, and slipped into bed. He was asleep as soon as his head hit the pillow, so he didn't notice when a soft white light enveloped him. It was some of the left over Chaos magic and his own reacting together to remove the charms and potions that had been affecting him for the almost seventeen years of his life were removed leaving the teen as he should have been. His hair darkened until it was black, and his features sharpened and became more aristocratic. If his eyes had been open they would have been seen to change from soft brown to a piercing icy blue. The light dissipated leaving a very changed Xander Harris behind.

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**Please review.**

**This has also been published over on TTHellmouth, under Xandersgirl.**


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